Gao's work dates mostly to the Jian'an Era of the Xian Emperor, the last emperor of the Eastern Han dynasty. Gao wrote commentaries on the Spring and Autumn Annals ordered by Lü Buwei; the Classics of Filial Piety and of Mountains and Seas; the Huainanzi; The Strategies of the Warring States; Discourse Weighed in the Balance; and the collected works of the philosopherMencius. Gao began his Notes on the HuainanziHuáinánzi Zhù) while studying under Lu and then completed his full commentary in 212. The Huainanzi had become important by his time because it was used to "verify" or "test" the genuineness of editions and commentaries of other classics. Charles Le Blanc argues that the phrasing of Gao's preface to his edition of the Huainanzi indicates that still had notes from his former teacher to consult; he also argues that Gao's commentary presumably incorporates the highlights of the otherwise lost work by Lu's own teacher Ma Rong. By the time he finished his work on the Huainanzi, Gao had also already completed his notes on the Classic of Filial Piety and the collected works of Mencius. The latter is now lost. Gao wrote his commentary on Master Lü's Spring and Autumn Annals next, presumably under the influence of Lu's own work on that text. Most of his preface consists of a biography of its chief editor, the Qinchancellor Lü Buwei. This account mostly repeats the biography of Lü found in Sima Qian's Records of the Grand Historian. He defends the work's importance—equating it to Liu An's Huainanzi, Yang Xiong's Model Sayings, and the collected works of Xun Kuang and Mencius—by reference to its inclusion in the official bibliographies compiled by Liu Xiang and Liu Xin. Gao's commentary on the Strategies of the Warring States appears to have been its first. It is now lost, except for the parts that were included in the later Song-era commentary by Yao Hong.
Legacy
Current editions of the Huainanzi derive in part from copies of Gao's commentaries on it. He commented on all 21 chapters of the original text, but only 13 survive in full. Although the authenticity and completeness of the eight chapters now taken from Xu Shen's alleged commentary are both questioned, Gao's chapters are thought to represent survivals of a genuine copy of the original text. The sinologist Victor Mair considers Gao You responsible for the current organization of the Strategies of the Warring States. Gao's commentaries on the Huainanzi and Master Lü's Spring and Autumn Annals include numerous asides on the pronunciation of certain characters, particularly in his local dialect. His notes on the Huainanzi also includes material on the peculiarities of the usual dialect in the former area of Chu. Baxter and Sagart have used some of these notes in their reconstruction of the pronunciation of old Chinese. Gao's note that his copy of Master Lü's Spring and Autumn Annals, which he considered in "poor condition", consisted of 173,054 characters is significant to scholarship concerning that text, since it makes his edition about a third longer than any currently existing.
